In an unprecedented move, China's defence ministry has reportedly issued a formal apology after an image of the nation's recently launched first aircraft carrier appearing on the ministry's social media accounts was mocked by the internet for being poorly photoshopped.

According to reports, the poster appeared on the ministry's Weibo and WeChat accounts over the weekend, and was meant as a celebratory token to mark the People's Liberation Army Navy's 68th birthday. However, the image featured American warships and Russian fighter jets alongside the aircraft carrier.

Defence ministry spokesman Yang Yujun said he was "sincerely sorry" that the image was "not meticulous".

"The carelessness was with the editor, the responsibility is on the shoulders of the leadership," Yang said at a monthly news briefing," the South China Morning Post reported.

The poster featured images of a Russian MiG-35 and three other fighter jets that instead of being carrier-based J-15s were land-based J-10s.

Users of Weibo, which is considered China's version of Twitter, reportedly slammed the Chinese military for allowing the poster to be released thus. "Those propaganda guys are weak in the head. They need to go after them for not doing their job," wrote one Weibo user.

"This poster is the standard of a street photocopy shop," another user wrote.

Despite the criticisms, the ministry refused to take down the poster as a "gesture" to the public in the face of "good-willed criticism".

"We believe that the harsh criticisms [from netizens] reflected their deep love and heartfelt support to us," Chinese local media quoted Yang as saying. "Leaving the picture along with the appended comments was an alert for us. It serves as a constant reminder to us about working hard and to keep progressing.

"On behalf of our editing team, we offer our sincere apology as well as gratitude to people who pay attention to us, care about us and support us".